Hypodermic syringe with spring biassed piston

ABSTRACT

1,008,915. Hypodermic syringes. G. DAUELSBERG [trading as PENICILLINGESELLSCHAFT DAUELSBERG CO.] Oct, 8. 1962 [Oct. 7, 1961; May 29, 1962], No. 37954/62. Heading A5R. An ampoule-needle unit for use in conjunction with a plunger in a hypodermic syringe, comprises a cylindrical sleeve 1 sealed at each end by a vapour-tight plug 3, 7 and containing a cannula 5 with a point at each end and a transparent synthetic plastics ampoule 2, the plug and the end of the ampoule adjacent the cannula being pierceable by the cannula and the ampoule being sealed at its other end by a plunger plug 3. The plunger plug and the plug sealing the cylindrical sleeve are the same. The cannula is slidably mounted in a socket 4 at the front of the ampoule. The ampoule and cannula are slidable in the sleeve 1. Actuating mechanism comprises a casing 9 in the forward end of which the ampoule-needle unit is secured by a spring ring 12. A piston 13, which abuts the plug 3 when the device is assembled, has a shaft 15 which passes through the rear end of the casing 9 and has a collar 20 which enables it to be locked in retracted position against a spring 18. A release cap 19 is mounted over the rear end of the casing and the piston shaft. Bevelled rollers 32 (Pyure 3) mounted on axle pins 31 are held in engagement with the piston shaft by a retainer ring 24. An extension 33 of one axle pin rests against the base of the cap 19. To release the piston, the cap is rotated so that the axle pin extension enters a recess 34 and then is moved axially to displace the retainer ring, so that the rollers move apart and permit projection of the piston by the spring.

M y 11, 1965 w. WEYDANZ ETAL 3,182,660

HYPODERMIC SYRINGE WITH SPRING BIASSED PISTON Filed Oct. 5, 1962 4 Sheets-Sheet 1 Fig. 2 Fig. I 8 11 6 7F Inve lors:

y 11, 1965 w. WEYDANZ ETAL 3,182,660

HYPODERMIC SYRINGE WITH SPRING BIASSED PISTON Filed Oct. 5, 1962 4 Sheets-Sheet 2 t 4 Fig.3 f3

30 Z 1 H7 Z7- 25 II 4 If Y I i v Fig.6 2?

Inventors 3,182,660 HYPODERMIC SYRINGE WITH SPRING BIASSED PISTON Filed Oct. 5, 1962 1965 w. WEYDANZ ETAL May 11 4 Sheets-Sheet 4 United States Patent 3,182,660 HYPGDERMIC SYRINGE WITH SPRING BIASfiED PESTON Wilhelm Weydanz, Bruder Grimm Allee 22, Gottingen,

Germany, Walter Huhensack, Konigsallee 5, Gottirrgen, Germany, and Rudi Ronnenberg, Weenderlandstr. 80, Gottingen, Germany Filed Oct. 5, H62, Ser. No. 229,283 Claims priority, application Germany Oct. 7, 1961,

P 28,001; May 29, 1962, P 29,506

4 Claims. (Cl. 128-218) The present invention relates to a hypodermic syringe which is advantageously used for hypodermic injections by the patient himself. 1

Syringes of this type known hitherto do not meet requirements satisfactorily. They consist of a housing accommodating the ampule and an injection needle sliding therein and having two pointed ends, as well as of a piston subjected to the action of a compression spring and sliding in the housing, and a locking and release mechanism for the piston which upon release of the locking mechanism and through means for the relieved spring drives the needle out of the housing so that the contents of the ampule are discharged through the needle.

The material requirements for the production of such syringes are high and prevent the syringe from being used only once as is desired today. For reasons of a long storability, glass or metal ampules had to be used. An ampule made of glass, however, breaks easily and necessitates a most careful handling of the syringe. Metal ampules are suitable for certain medicaments only. Furthermore, they are not transparent and their contents cannot be controlled for foreign matter or air bubbles. The requirement of sterile assembly and storage of the ampule or the hypodermic needle could hardly be met. Eventually, operation of the syringe was diflicult, which is of great importance, because the user might have some kind of fear when making the injection on himself. He might be tempted to withdraw the syringe from the body a short moment before the decisive action, so that the injection is interrupted or not carried out at all.

It is one object of the present invention to provide a syringe, which eliminates all of the deficiencies of known embodiments of hypodermic syringes.

It is another object of the present invention to provide a syringe, wherein a housing accommodates the ampule with the needle and the actuating mechanism for the syringe each form self-contained units which can be assembled and replaced to form the complete syringe. Thus, it is possible to use the ampule and the needle only once, while the part of the syringe containing the actuating mechanism can be re-used for further injections. Furthermore, it is also possible to exchange the chamber with the ampule and the needle, when another ampule filling is necessary.

It is still another object of the present invention to provide a syringe, wherein a transparent, unbreakable ampule, made of plastic material for instance, is used, which is accommodated in a vapor-proof, closed chamber. The unit containing the actuating mechanism is conveniently fitted in a long housing, the forward part of which is designed to replaceably receive the chamber containing the ampule unit.

The transparent ampule of plastic material enables a control with respect to foreign matter and air bubbles. It is unbreakable and since it is accommodated in a vapor-proof chamber, a long storability of the hypodermic syringe is possible. Without a vapor-proof sealing, the contents would gradually escape through the walls of the plastic ampule.

Preferably, a shaft of the piston for actuating the hy- 3,182,660 Patented May 11, 1965 "ice podermic syringe extends through the bottom of the housing against which rests the compression spring acting on the piston, the end of the shaft having an external projecting collar tapered on both sides, while on the outside of the housing bottom radially movable locking members are arranged around the piston shaft in a manner, so that in their inner end position they engage behind the collar and are enclosed by means of a retainer ring located in a release cap and axially displaceable with the latter, which is axially displaceable on the housing, so that in its other end position the retainer ring releases the locking members to enable the latter to be moved radially in outward direction by the advancing piston which is thus released. Conveniently, the locking members consist of balls or rollers which are engaged or released by the axially displaceable release member, so that they engage behind the collar provided on the piston shaft or are moved in outward direction by the collar through the action of the compression spring acting on the piston. Thus, a particularly easy and sensitive release of the hypodermic syringe is obtained and after the injection a simple return and locking of the piston is possible when the spring is tensioned again. It is another advantage that the locking members are rigid parts which are not subjected to particular wear even after frequent use of the hypodermic syringe, as might be the case, when the locking members are formed of or attached to springs which design, of course, is also possible without departing from the spirit of the present invention.

With these and other objects in view, which will become apparent in the following detailed description, the present invention will be clearly understood in connection with the accompanying drawings, in which:

FIGURE 1 is an axial section of the ampule unit;

FIG. 2 is an axial section of the unit incorporating the actuating mechanism, without the locking means for the piston shaft and the release means;

FIGS. 3, 4, S and 8 are fragmentary axial sections of different embodiments of the locking means for the piston shaft, accommodated in the release cap;

FIG. 6 is a section along the lines 6-6 of FIG. 3;

FIG. 7 is a section taken along the lines 77 of FIG. 4; and

FIG. 9 is a section along the lines 9-9 of FIG. 8.

Referring now to the drawings, and in particular to FIGS. 1 to 3, a housing accommodating the ampule is disclosed. Substantially, it consists of a cylindrical container 1 to guide an ampule 2 containing the solution for the injection. The ampule 2, as well as the container 1 are closed by a piston-like plug 3. At its forward end, the ampule 2 is provided with a socket 4 receiving a slidable hypodermic needle 5, which is tapered at both ends. A point of the hypodermic needle 5 is disposed opposite a diaphragm 6 closing the ampule 2. The forward end of the needle 5 projects into a plug 7 closing the container 1 at the needle end. This end is in front of another diaphragm 8 which is pierced by the needle 5 when the latter is actuated.

After filling and closing under sterile conditions, the container 1 forms a self-contained unit which can be handled without endangering the sterility of its contents.

Referring now to FIG. 2, a sectional view of the part of the syringe incorporating the actuating mechanism is disclosed, which substantially consists of a housing 9 having an extension 10 to receive the ampule unit shown in FIG. 1. A collar 11 is'provided at the front end of the housing part 10, to accommodate a replaceable spring ring 12 which retains the entire ampule unit in the housing 10. A piston 13 is guided in the rear part of the housing 9, which piston 13 rests with its forward collar 14 on the piston-like plug 3 of the ampule 2 when the different parts are fitted into each other and which piston 13 has a shaft 15 projecting through an opening 16 in the housing bottom 17. A compression spring 18 1S arranged inside the housing 9 between the housing bottom 17 and the collar 14 at the forward end of the'piston 13 to actuate the latter. A release cap 19 extends over the rear end of the housing9.

In the initial position of the hypodermic syringe, the tensioned compression spring 18 must be secured. For this purpose, the end of the piston shaft 15 is provided with an external collar 29 tapering at both sides and cooperating with suitable locking means. In the embodiment disclosed in FIG. 3, locking means are used which are formed of tongues 21 arranged around the piston shaft 15, fixed in the housing bottom 17 and having near their ends an inner shoulder 22. The latter engages behind the collar 20. On the other hand, the ends of the tongues 21 are provided with guides 23 to support the tongues 21 in a retainer ring 24 which is inserted into the inside of the release cap 19. The ring 24 has a collar 25, engaging behind the guides 23 of the locking members 21, thereby securing the release cap 19 against accidental withdrawal from the housing 9.

The release cap 19 is fitted in a manner suchthat a chamber 26 is formed at its bottom which accommodates a cam disc 27. The latter is arranged eccentrically on a shaft 28 of a set button 29 journalled in the release cap 19, and it is dimensioned such that by rotating the button 29 axis of the latter can be turned into the axis of the inner chamber 30 inside the locking members 21.

The position of the different parts in initial position of the syringe is illustrated'in FIG. 3. By means of the cam 27 the release cap 19 rests on the ends 23 of the locking members 21, so that no axial displacement of the release cap 19 can take place. Only after rotation of the button 29 and, thereby, of the axis of the cam 27 to coincide with the axis of the empty chamber 30, can the release cap 19 be pushed further axially over the housing 9. The retainer ring 24 is removed from the guides 23 of the locking members 21 which are no longer enclosed. The tensioned compression spring 18 acting on the piston 13 drives the latter forward, thereby spreading the locking members 21 by means of the conical collar 20 and the cam-shaped projections 22 on the locking members 21, so that the latter actually release the piston.

On the other hand, by means of a suitable tool, the piston 13 can be returned into its initial position, when after removal of the entire ampule unit the piston 13 is forced back. During this operation, the collar 20 slides over the collars or neck portions 22 of the locking members 21. In the rear end position of the piston 13 the release cap 19 is withdrawn somewhat from the housing 9, so that the retainer ring 24 again encloses the locking members 21. By rotating the adjusting button 29, the cam 27 is turned back into its locking position. Thus, the actuating mechanism is locked again in its initial position.

Referring now to the embodiment disclosed in FIG. 4, the piston 13 is locked by means of rollers 32 having conical ends and being journalled with considerable play on axial pins 31 on the outside of the housing bottom which is shaped accordingly, the rollers 32 engaging behind the collar 20 on thepiston shaft 15 and bearing against the inside of the retainer ring 24 of the release cap 19.

One of the pins 31 has an extension 33 which rests on the thick bottom of the release 19. For the extension 33, the bottom of the cap is provided with a recess 34.

The operation of the parts is the same as shown in FIG. 3. When the release cap 19' is rotated so that the recess 34 in the bottom of the cap 19' is in alignment with the pin 33, the release cap 19 can be moved axially and the retainer ring 24 for the locking rollers 32 can be transferred into its release position. Due to'the shape of 4 the rollers 32 and the collar 20 on the piston shaft 15, the parts are spread apart through means of the action of the compression spring 18 and the piston is released. When reversing these operations, the piston is forced back and the spring 18 is tensioned again.

A simplified embodiment of the hypodermic syringe is disclosed in FIG. 5. The collar 20 on the piston shaft 15 is enclosed by resilient retainer members 35 which are fixed at the bottom of the release cap 19 and which are provided, at their ends, with two recesses 36 and 37 disposed behind one another. Furthermore, the ends 38 of the springs 35 are bent outwards. To actuate the springs 35, the bottom of the release cap 19 is provided with a push-button 39 which with its head 40 rests on the first recess 36 of the springs. In this embodiment, the release cap 19 is fitted to the housing 9 so that it cannot be moved axially.

In the initial position, the piston shaft 15 is held by means of the parts 35 in that their recesses 37 engage behind the collar 20.

By pressing the button 39, the spring is radially forced outwards so that the recesses 37 release the collar 20 to enable the piston to be pushed forward through means of the action of the spring 18. When tensioning the piston, however, the collar 20 bears on the outwardly bent ends of the springs 38. These are spread apart and their bent portions 37 again rest behind the collar 20.

In the embodiment of the actuating mechanism according to FIGS. 8 and 9, the housing 9 is provided, behind its bottom 17 with an extension guiding a release ring 46. The latter has an inner collar 47. The ring is also guided by means of the collar 47 to be axially displaceable on a bushing 48 which encloses the piston shaft 15' and which is provided on the housing bottom 17.

The ring 46 is provided with a small bore 49 and a Wide bore 50. The locking members in this case are formed of balls 51 which are arranged around the piston shaft 15', have a rather wide bore 52 and are secured in their circular arrangement around the piston shaft 15 by means of a retainer ring 53.

The release ring 46 extends beyond the housing extension 45 and is provided with a cover 54 closing the housing 9 On the other hand, the rim of the housing 45 has recesses 55 to receive projections provided on the cover 54 when the latter is rotated together with the release ring 46.

When the compression spring 18 acting on the piston is tensioned, the release end of the hypodermic syringe is conveniently turned up and the piston pressed into the housing 9'. The piston shaft 15' and its collar 20 then penetrates the locking balls 51. The release ring 46 is now withdrawn from the housing until tthe balls which engage below the collar 20' have entered the recess 49. At this moment the piston is secured in its initial position. The cover 54 with the ring 46 has to be turned until its projections clear the recess 55 provided in the housing 45. If, however, the syringe is actuated, the cover 54 with the ring 46 is turned until it can be axially displaced. The recess 49 releases the locking balls 51 which are held by the end of the bushing 48. They enter the wide bore and are radially spread apart through means of the surface on the collar 20' until the piston is released and driven forward through means of the action of the tensioned spring 18.

While we have disclosed several embodiments of the present invention, it is to be understood that these embodiments are given by example only and not in a limiting sense, the scope of the present invention being determined by the objects and the claims.

We claim:

1. A hypodermic syringe for self administering injections comprising a first unit and a second unit receiving said first unit,

said first unit comprising a cylindrical housing open at one end and having a bottom wall to close the other end,

said bottom wall defining a central opening,

a release cap telescopically surrounding said closed other end of said cylindrical housing,

a piston having a shaft extending therefrom and disposed in said cylindrical housing adjacent said bottom wall and said shaft extending through said central opening of said bottom wall,

said piston having a collar at its end remote from said shaft,

a compression spring in said cylindrical housing and engaging the inner face of said bottom wall and said collar of said piston, respectively, thereby urging said piston into the innermost position in said cylindrical housing,

releasable locking means cooperating with said shaft for retaining said piston in its Withdrawn position against the force of said compression spring, and

said second unit comprising a cylindrical metal container fittingly and immovably disposed in and at the open end of said cylindrical container,

an ampule of plastic material immovably received in and at the inner end of said metal container and disposed adjacent said piston,

a first diaphragm closing one end of said ampule,

a first plug disposed at the other end of said ampule and axially displaceable in the latter,

said plug engaging the end face of said piston and being actuated by the latter,

a second plug secured to and retained at the outer end of said metal container,

a second diaphragm disposed in said second plug,

a hypodermic needle axially m ovably disposed in said metal container between said first diaphragm and said second diaphragm and having pointed ends,

so that upon releasing of said locking means said piston pushes by means of said compression spring said first plug into said ampule simultaneously piercing both said diaphragms by the pointed ends of said hypodermic needle in order to discharge the content of said ampule through said axially moved hypodermic 6 needle and said ampule is. retained vapor-proof and sterile in said metal container. 2. The hypodermic syringe, as set forth in claim 1,

which includes means for retaining said metal container in a predetermined position in said cylindrical housing. 3. The hypodermic syringe, as set forth in claim 1,

wherein said cylindrical metal container is set off inwardly at its open end to form an inner diameter substantially identical with the inner diameter of said ampule and the outer diameter of said first plug.

4. The hypodermic syringe, as set forth in claim 1,

which includes References Cited by the Examiner UNITED STATES PATENTS 2,664,086 1'2/53 Transue 128-218.2 2,762,370 9/56 Venditty 128-173 2,832,339 4/58 Sarnoff et a1. 128-218.2 2,866,458 12/58 Hein 128-218.2 2,871,856 2/59 Steiner 128-216 3,066,670 12/62 Sta'ufier 128-218.2

FOREIGN PATENTS 1,249,255 11/60 France. 1,081,192 5/60 Germany.

40 RICHARD A. GAUDET, Primary Examiner.

JORDAN FRANKLIN, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,182,660 May 11; 1965 Wilhelm Weydanz et a1.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4, line 74, for "receiving" read received by column 5, line 23, for "immovably" read movably column 6, 1 line 10, for "open" read rear line 20, for "open read front Signed and sealed this 29th day of March 1966.

( L) Attest:

ERNEST W. SWIDER Attesting Officer EDWARD]. BRENNER Commissioner of Patents 

1. A HYPODERMIC SYRINGE FOR SELF ADMINISTERING INJECTIONS COMPRISING A FIRST UNIT AND A SECOND UNIT RECEIVING SAID FIRST UNIT, SAID FIRST UNIT COMPRISING A CYLINDRICAL HOUSING OPEN AT ONE END AND HAVING A BOTTOM WALL TO CLOSE THE OTHER END, SAID BOTTOM WALL DEFINING A CENTRAL OPENING, A RELEASE CAP TELESCOPICALLY SURROUNDING SAID CLOSED OTHER END OF SAID CYLINDRICAL HOUSING, A PISTON HAVING A SHAFT EXTENDING THEREFROM AND DISPOSED IN SAID CYLINDRICAL HOUSING ADJACENT SAID BOTTOM WALL AND SAID SHAFT EXTENDING THROUGH SAID CENTRAL OPENING OF SAID BOTTOM WALL, SAID PISTON HAVING A COLLAR AT ITS END REMOTE FROM SAID SHAFT, A COMPRESSION SPRING IN SAID CYLINDRICAL HOUSING AND ENGAGING THE INNER FACE OF SAID BOTTOM WALL AND SAID COLLAR OF SAID PISTON RESPECTIVELY, THEREBY URGING SAID PISTON INTO THE INNERMOSE POSITION IN SAID CYLINDRICAL HOUSING, RELEASABLE LOCKING MEANS COOPERATING WITH SAID SHAFT AND RETAINING SAID PISTON IN ITS WITHDRAWN POSITION AGAINST THE FORCE OF SAID COMPRESSION SPRING, AND SAID SECOND UNIT COMPRISING A CYLINDRICAL METAL CONTAINER FITTINGLY AND IMMOVABLY DISPOSED IN AND AT THE OPEN END OF SAID CYLINDRICAL CONTAINER, AN AMPULE OF PLASTIC MATERIAL IMMOVABLY RECEIVED IN AND AT THE INNER END OF SAID METAL CONTAINER AND DISPOSED ADJACENT SAID PISTON, A FIRST DIAPHRAGM CLOSING ONE END OF SAID AMPULE, A FIRST PLUG DISPOSED AT THE OTHER END OF SAID AMPULE AND AXIALLY DISPLACEABLE IN THE LATTER, SAID PLUG ENGAGING THE END OF SAID PISTON AND BEING ACTUATED BY THE LATTER, A SECOND PLUG SECURED TO AND RETAINED AT THE OUTER END OF SAID METAL CONTAINER, A SECOND DIAPHRAGM DISPOSED IN SAID SECOND PLUG, A HYPODERMIC NEEDLE AXIALLY MOVABLY DISPOSED IN SAID METAL CONTAINER BETWEEN SAID FIRST DIAPHRAGM AND SAID SECOND DIAPHRAGM AND HAVING POINTED ENDS, SO THAT UPON RELEASING OF SAID LOCKING MEANS SAID PISTON PUSHES BY MEANS OF SAID COMPRESSION SPRING SAID FIRST PLUG INTO SAID AMPULE SIMULTANEOUSLY PIERCING BOTH SAID DIAPHRAGMS BY THE POINTED ENDS OF SAID HYPODERMIC NEEDLE IN ORDER TO DISCHARGE THE CONTENT OF SAID AMPULE THROUGH SAID AXIALLY MOVED HYPODERMIC NEEDLE AND SAID AMPULE IS RETAINED VAPOR-PROOF AND STERILE IN SAID METAL CONTAINER. 